Cooler and exhaust tubulation for external anode electron tubes



June 24, 1947. M, E. WOLFE 2,422,872

COCLER AND EXHAUST TUBULATION FOR EXTERNAL ANODE ELECTRON TUBES Filed July 6, 1945 6 r 4 12 V /3 I /3 I INVENTOR. Mari/r7 E. Wolfe ATTORNEY Patented June 24, 1947 COOLER AND EXHAUST TUBULATION FOR EXTERNAL AN ODE ELECTRON TUBES Martin E.Wolfe, Lomita Park, Calif., assignor to Eitel-McCullough, Inc., San Bruno, Calif., a corporation of California Application July 6, 1945, Serial No. 603,471

3 Claims.

My invention relates to an electron tube of the type in which the anode forms part of the envelope wall.

The broad object of my invention is to provide a tube of the character described having an improved exhaust tubulation.

The invention possesses other objects and fea tures of advantage, some of which, with the foregoing, will be set forth in the following description of my invention. It is to be understood that I do not limit myself to this disclosure of species of my invention as I may adopt variant embodiments thereof within the scope of the claims.

Referring to the drawing:

The figure of the drawing is an axial sectional view of a tube embodying the improvements of my invention.

In terms of broad inclusion, my tube comprises an envelope, a metallic anode forming part of the envelope wall, and an exhaust passage in the anode ported into the envelope. A metallic tubulation on the anode registers with the exhaust passage, and protective means is preferably provided on the anode to encircle the tubulation. In my preferred construction a cooler is arranged on the anode with a portion disposed about the tubulation to form the protective means. Other desired electrodes such as a cathode and grid are suitably mounted in the envelope.

In greater detail, and referring to the drawing, my tube comprises a metallic anode 2, preferably cup-shaped, forming part of the envelope Wall. The remainder of the envelope comprises a vitreous or glass portion 3 fused to flare 4 of the anode at seal 6. Portion 3 preferably has a reentrant stem 1 for carrying the other electrodes in the tube.

Cathode 9 extends upwardly into anode 2 and comprises a helix of thoriated tungsten wire secured top and bottom to a. pair of cathode leads l9 sealed to stem 1. Grid II of the cage type also extends into the anode and is supported by brackets l2 on rods l3 sealed to stem 1, one of these rods functioning as a grid lead. A suitable base !4 is secured to the glass portion of the envelope by cement I6. This base carries terminal prongs ll to which flexible extensions on the grid and cathode leads are connected.

The tube above described is merely for purposes of illustration, and may be varied widely in its construction, it being understood that my improvements may be incorporated in any tube wherein the anode forms part of the tube envelope.

2 In making vacuum tubes the usual practice is to exhaust the tube through a glass tubulation attached to the glass portion of the envelope. This is not desirable because it complicates the structure. My improved tube has an exhaust passage l8 ported into the envelope through anode 2. With the preferred cup-shaped type of anode, passage I8 is located in the end wall. A metal exhaust tubulation I9 is secured as by brazing to the anode in registration with passage [8, and preferably extends outwardly along the anode axis. After exhaust, the tube is sealed by mechanically pinching off the tubulation at tip 2|. A suitable cooler having a core 22 and radial heat radiating fins 23 is attached to the cylindrical Wall of the anode, as by soldering.

Means carried by the [anode is provided on the tube for protecting the exhaust tubulation, as damage to this part by impact or otherwise could cause a leak and destroy the vacuum in the envelope. This is an important feature because it not only prevents damage occurring to the tubulation, but also improves the appearance of the tube. In my preferred tube the protective means is formed by the cooler structure, core 22 being of suflicient length so that it extends beyond the end of anode 2 to provide a sleeve disposed about tubulation IS. The end of the cooler is preferably closed by a domed cap 24 attached to core 22. If desired, cooler core 22 may be terminated adjacent the end of anode 2, and cap 24 of the cooler structure so shaped as to provide a protective housing about tubulation Hi. In this event, the dome of cap 24 is preferably drawn more deeply than that illustrated to provide a cup-shaped closure for housing the tubulation.

I claim:

1. An electron tube comprising an envelope, a metallic anode forming part of said envelope, a cathode in the envelope, an exhaust tubulation projecting from the anode ported into the envelope, and a cooler structure on the anode having a portion enclosing said tubulation.

2. An electron tube comprising an envelope, a cup-shaped metallic anode forming part of said envelope, a cathode in the envelope extending into the anode, an exhaust tubulation projecting from the outer end of the anode ported into the envelope, and a cooler structure on the anode having a portion enclosing said tubulation.

3. An electron tube comprising an envelope, a metallic anode forming part of said envelope, a cathode in the envelope, an exhaust tubulation projecting from the anode ported into the envelope, and a, cooler structure on the anode, said cooler structure having a hollow portion providing a protective housing for said tubulation.

MARTIN E. WOLFE.

REFERENCES CITED The following references are of record in the file of this patent:

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